Inhibition of Insulin like growth factor-I expression by chromatographic fraction of Polygonum hydropiper root reduces implantation preference in rat

Abstract

Study objective: Objective of the investigation was to determine if, the phytocompound(s) present in the root of Polygonum hydropiper could inhibit implantation mediating the regulation of Insulin like growth factor (IGF-I) mRNA transcript. Design: A prospective study. Setting: Department of Zoology of Rajiv Gandhi University. Materials and methods: The root extract of P. hydropiper was fractionated by thin layer chromatography using estradiol-17β (E2) as reference compound. The fraction with a similar Rf value as that of E2 was administered subcutaneously to pregnant rats in a dose of 5 mg/kg body weight from day 1 to day 6 of gestation. Implantation sites were counted on day 6 of gestation. Expression of IGF-I in situ was localised in paraffin embedded sections where in, mRNA transcript was studied by RT-PCR in uterine tissues from day 2 to day 6 of gestation. Main outcome measure: Inhibition of embryo implantation mediating regulation of Insulin like growth factor (IGF-I) mRNA transcript. Results: Pregnant female rats treated with chromatographic fraction showed a decreased number of implantation sites. The inhibition of implantation by the chromatographic fraction of the root extract of P. hydropiper was associated with failure of decidual cell reaction in the primary decidual zone. During this critical period of fetal–maternal interaction the number of IGF-I mRNA transcripts gradually decreased resulting in a decreased expression of the growth factor in uterus. Major conclusions: The root of P. hydropiper contains compound(s) with capability to modulate transcription and expression of IGF-I in rat uterus during early gestation. Down regulation of IGF-I results suggests that the phytocompound(s) work through the ovarian steroid receptor(s) resulting in an inhibition of decidual cell reaction and implantation.

Keywords

• TLC fraction
• Polygonum hydropiper
• Insulin like growth factor (IGF-I)
• IHC
• RT-PCR